Ginkgo Biloba: Hype or hope?

Last week, Peter and I gave a talk sponsored by the Political Science department at Case Western Reserve University. One question posed to us inquired as to which type of major media stories represent true sources of hope.

We referred the questioner to our previous post that outlined how to distinguish hype from hope and recognize the commercial interests of those offering simplistic “fixes”, but fell short of rejecting the notion that pharmaceuticals and herbal supplements can offer help in delaying the onset of brain aging.

The three-year study involved 118 people age 85 and older with no memory problems. Half of them took ginkgo biloba extract three times a day and half took a placebo.

During the study, 21 people developed mild memory problems, or questionable dementia: 14 of those had taken the placebo and 7 had received the ginkgo extract. Although there was a trend favoring ginkgo, the difference between those who took ginkgo and those who took placebo was not statistically significant. However, when the researchers took into account whether people accurately followed directions in taking the study pills, they found that people who reliably took ginkgo had a 68 percent lower risk of developing mild memory problems than those who took the placebo.

While the supplement appeared to send some positive signals, the study also showed a higher incidence of strokes and “mini-strokes” in ginkgo users.

And so, hope must be tempered by the uncertainty that remains about ginkgo’s mechanism of action and the peripheral effects (such as stroke) that the supplement might induce. Readers must remember that this is a relatively small study that is far from definitive, but which can help us develop more specific, testable hypotheses about the effects and safety of ginkgo.

Lastly, readers must be wary of the commercial interests that inflate our hope about ginkgo. Indeed, the herb is often marketed irresponsibly as a “memory enhancer,” and different suppliers offer products that differ in their amount of active ingredients.